Exploring Re-Activation

In recent posts, Robin mentioned that reactivation is important for x and Bob mentioned that a good description of it might be y. I'd like to start a discussion about this topic in general to deepen my understanding of it. I have a few questions to start:

a) How would we define re-activation?b) Why call it re-activation? Why not just activation?c) What exactly is getting activated?d) Why is activation important in Coherence Therapy?